Gender discrimination is common in China and it does not necessarily mean that a given school is bad and in fact, I know of many licensed and well respected schools and ESL institutes alike that have a specific gender requirement because they serve a specific demographic such as an all girls school as an example. I have seen this with boarding schools, various religious schools, and others that were in business for at least 50-years so your comments are not completely with merit. In the case of teaching very young kids, most parents request female only teachers as yet another example. The school that I currently work at has been in business for about 17-years and they only hire female teachers.